Sheet-feeding device



H. T. BACKHOUSE SHEET FEEDING DEVICE V Filed Feb. 28, 1924 2Sheets-Sheet 2 Ti" 5 TAT ES Param ortica.

EEADLEY TOWNSEND OF LONON, ENGLAND.

`SHEET-FEEDNG DEVCE.

Application filed February 8, 1924. Serial No. 695,865,` and vintl-reetBritain-April l0, 1923.

. sheet is-arrested by two or more registering marks.

stops usually termed the front la-ys or lay The front lays `insure thateach sheet is brought into the same position, as regards the-alignmentof its forward edge, before being passed on to the printing or likemachine.

It is desirable, particularly with modern requirements of high-speedoutput from sheet-feeding apparatus, that the initial travel of thesheet vfrom the sheet pile towards the front lays should becomparatively rapid but that the sheet should be slowed up immediatelybefore it reaches the front lays so that it will not rebound therefrom.The present invention is concerned with vmeans for controlling the speedat which the sheets are conveyed by the feeding apparatus so that theabove requirements will be fulfilled.

rilhis invention provides in combination with sheet-feeding apparatusfora printing press or other machine operating on paper or like sheets,variable speed driving mechanism for the sheet-feeding means, comprisingtwo cranks or equivalent devices of unequal lengths, one constitutingthe driving member and the other the driven member of the mechanism,saidrcranks being rotatable about parallel axes located as specifiedhereunder and being coupled by a pin, stud or other projection from thesmaller crank in engagement with a radially or substantially radiallydirected slot or guide in or on the larger crank.

The location of the axes of the two cranks is such that the circle ofrevolution of the smaller crank, when projected on to the plane ofrotation of the larger crank, will lie within the circle of revolutionof said larger crank. This arrangement insures that, durinc' therotation of the cranks about vtheir respective axes, one being rotatedby the other, thc pin on the smaller crank will at all times remain inengagement with the guide on the larger crank. Variable speed mechanismof this general type has hitherto been proposed for purposes other thanthat with whichthe present invention is concerned, and no claim is madeherein to this mechanism per se.

ln one form of the present invention each of the twov cranks aforesaidis constituted by .a disc carrying at its periphery, or having .itsperipheryV formed as, a toothed ring for the transmission of the driveto and from the mechanism.

One example of this invention will now be described with reference tothe accompanying drawings, in whichvFigure 1 isa cross-section through avariable speed gear-box embodying the invention;

Figures 2 and 3 the operation of the mechanism;

Figure 4i is a similar diagram showing a` modification in thedisposition of the guide on the larger crank;

Figure 5 is a diagram similar to-Figure 4 and illustrating ya possiblemodification in the shape of the guide.

Like reference numerals indicate like parts in the various figures.

The arrangement shown in Figures 1 2 and 3 will first be described. Thetwo cranks are constituted by disc members 10 and 11, the formercorresponding to the larger crank and the latter to the smaller crank.The discs 10 and 11 are formed integrally with or are secured toshaftsl2 and 13 which are mounted for rotation in bearings .14, 15 carried ina gear-box or housing'16. The two discs 10, 1l are unequal in diameterand are mounted face to face with their axes of rotation parallel. Thediscs are so placed that there is one point in the periphery of cach atwhich the edges of the discs are in line with each other-that is,considered in a direction along the laxes of the discs. In Figure 1 theposition of alignment is at the right-hand side of the discs. Secured tothe smaller disc 11 near the periphery thereof is a stud 17 whichextends towards the disc 10 in a direction parallel with the axisthereof. Cut substantially radially across the face of the disc 10 is aslot 18 within which engages the outer end of the stud 17. This end ofthe stud is fitted with an anti-friction are diagrams illustratingrroller 1S) of such size that a slight clearance left between theperiphery of the roller and the side walls of the slot.

The disc 10 is formed with a bevel gear 20 which meshes vwith aco-operat-ing gearuvheel 21 carried by a shaft 22, constituting the maindriving or input shaft of the mecha nism. The disc 11 is driven by thepin-andslot connection aforesaid from the disc 10. Rotation of the disc11 is transmitted to a sleeve 25 through meshing gears 23 and 2li formedrespectively on the rim of the disc 11 and on the sleeve. From thesleeve 25 the drive passes through meshing gears 26 and 27 to a shaft 28Which constitutes the driven or output shaft of the mechanism.

ln operation the shaft 22, and therefore also the disc lO, is driven atconstant angular speed. lllhen the discs are in the position shown inFigure 2 the stud 17 is at the limit of its travel towards one end. ofthe slot 18. llvlhen in this position the part of the slot 18 whichengages the roller 19, that is the part of the disc 10 which transmitsmotion to the disc 11 is at a maximum operative distance from the centreof rotation of the disc 10 and is therefore rotating at a maximumperipheral speed. Under these conditions the angular speed of thesmaller disc 11 and therefore oi the output shaft 28 is a maximum. llhcnthe disk l0 has moved through a portion of a revolution the slot 18 andthe stud l? assume the position shovvn in Figure 8. is Will be seen theroller 19 has shifted radially inwards along the slot and the peripheralspeed of the driving portion of the disc l0 has now been considerablyreduced. rihe angular' velocity imparted to the disc 11 and therefore tothe output shaft, is consequently also reduced. lt is at this periodthat the slowing up of the sheetsfeeding means taires place.

Various modifications may be made in the shape and disposition of theslot in the disc member l() in order to vary the rate at which the speedof the final drive changes. The disposition of the slot is notnecessarily strictly radial although it Will always be in a generaldirection from the periphery towards the centre about which the disc 10rotates. For example the slot could be located slightly to one side ofthe centre as shown in Figure 4:, or again the slot may be curved itsends as illustrated in Figure 5.

it is to be understood that the direction in which the drive istransmitted through the mechanism may be reversed, that is to say, theshaft 28 may be the driving member and the snaft 22- the driven member.Under these conditions the smaller disc rotated at con stant angularvelocity and the variable speed is obtained from the larger disc. lnplace of the disc members described herein cranks or equivalent devicesmay obviously,v be em pl yed. Again instead of a slot out in the face ofthe disc 10 the latter may be formed with upstanding ribs constituting aguide to engage the roller 19.

1 claim 1. The combination with sheet feeding apparatus of theband-conveyor type of variable speed driving mechanism for the conveyorbands, said mechanism comprising in combination tivo disc-membersunequal in diameter and mounted face to face for rotation about parallelaxes, one disc-member constitilting` the 'drive and the other the drivenmember of the mechanism, a slot extending across the face of the larger'disc and having allel axes, one disc constituting the drivingy memberand the other the driven member of the mechanism, a substantiallydiametral slot in the face of the larger dise, a projection extendingfrom the face of the smaller disc into engagement With the slotaforesaid, and a toothed gear member carried at the periphery of each ofthe discs, the distance between the axes of the tivo discs being suchthat the projection Will remain in engagement with the slot in allangular positions of both discs.

In testimony whereof l adiX my signature.

HEADLEY TOWNSEND BACKHOUSE.

